The goals of this project are to collect clinical data and pathologic materials of retinal dysfunctions in man, and to establish comparable experimental animal models so that pathology, pathogenesis, natural course, treatment, and mechanisms of the treatment of these diseases may be studied at the clinical, histopathologic, and ultrastructural levels. 1. We will examine and categorize a unique collection of 200 cases of diseases of macula currently on file at the American Registry of Ophthalmic Pathology in an ongoing clinico-pathologic correlative study. Furthermore, additional clinical and pathologic materials of diseases of the macula and retina at the University of Illinois Eye & Ear Infirmary will be collected for in depth clinico-pathologic correlative studies. 2. We will examine the mechanisms of production, the pathologic manifestations, and the healing process of disruption of blood-retinal barrier at the retinal pigment epithelium and the retinal capillary in four experimental animal models: A) Macular edema in rhesus monkeys which had lens extraction and embarassment of the retinal circulation by photocoagulation. B) Macular edema in rhesus monkeys which had cyclocryotherapy. C) Disruption of blood-retinal barrier at the RPE and at the sub-RPE neovascularization in rhesus monkeys which had prolonged exposure to the light of an indirect ophthalmoscope. D) Disruption of blood-retinal barrier in intraretinal and vitreous neovascularization in kittens with retrolental fibroplasia, before and after various forms of photocoagulation therapy. The clinical data from the above experimental models will be documented by fundus and fluorescein angiography and vitreous fluorophotometry and will be correlated with the morphologic changes observed by light and electron microscopy and by horseradish peroxidase tracer technique.